1. Field of the Invention
The present invention generally relates to medical devices, methods, and systems, particularly for the treatment of urinary incontinence.
Urinary incontinence arises in both men and women with varying degrees of severity, and from different causes. In men, the condition frequently occurs as a result of prostatectomies which result in mechanical damage to the urinary sphincter. In women, the condition typically arises after pregnancy when musculoskeletal damage has occurred as a result of inelastic stretching of the structures supporting the genitourinary tract. Specifically, pregnancy can result in inelastic stretching of the pelvic floor, the external sphincter, and the tissue structures which support the bladder, urethra, and bladder neck region. In each of these cases, urinary leakage typically occurs when a patient""s abdominal pressure increases as a result of stress, e.g., coughing, sneezing, laughing, exercise, or the like.
Treatment of urinary incontinence can take a variety of forms. Most simply, the patient can wear absorptive devices or clothing, which is often sufficient for minor leakage events. Alternatively or additionally, patients may undertake exercises intended to strengthen the muscles in the pelvic region, or may attempt a behavior modification intended to reduce the incidence of urinary leakage.
In cases where such non-interventional approaches are inadequate or unacceptable, the patient may undergo surgery to correct the problem. A wide variety of procedures have been developed to correct urinary incontinence in women. Several of these procedures are specifically intended to support the bladder neck region. For example, sutures, straps or other artificial structures are often looped around the bladder neck and affixed to the pelvis, the endopelvic fascia, the ligaments which support the bladder, or the like. Other procedures involve surgical injections of bulking agents, inflatable balloons, or other elements to mechanically support the bladder neck.
In work done related to the present invention, it has been proposed to treat urinary incontinence by selectively contracting or shrinking a portion of the pelvic support tissue so as to reposition the bladder and/or urogenital tract. U.S. patent application Ser. No. 08/910,370 generally describes laparoscopic and other minimally invasive devices, methods, and systems for shrinking tissues, particularly for treatment of incontinence. U.S. patent application Ser. No. 09/133,496 describes noninvasive devices, methods, and systems for shrinking of tissues, often by cooling a surface of an intermediate tissue and directing energy through the cooled intermediate tissue to the target tissue so as to effect shrinkage. U.S. patent application Ser. No. 09/170,767 is directed to static devices and methods to shrink tissues for incontinence. Finally, U.S. patent application Ser. No. 09/103,352 describes tuck and fold fascia shortening for incontinence. Each of these applications is assigned to the present assignee, and their full disclosures are incorporated herein by reference.
While these recent proposals for treatment of incontinence represent significant advancements in the art, treatment of incontinence and other conditions related to insufficient tissue support could benefit from still further advances. In particular, it is generally beneficial to minimize collateral damage imposed on the treated and adjacent tissues during any therapy. It would further be beneficial to provide alternative treatment mechanisms for reducing or eliminating the severity and occurrence of incontinence events.
A variety of other problems can arise when tissues of the body fail to provide adequate support. Weakened pelvic support tissues (particularly the ligaments and fascia of the pelvic area) can lead to a variety of ailments including, for example, cystocele, prolapse, and the like. Cosmetic surgeries are also often performed to enhance the support provided by fascial tissues. For example, abdominoplasty (often called a xe2x80x9ctummy tuckxe2x80x9d) is often performed to enhance support provide by the abdominal wall. The distortion of these support tissues may be due to strain, advanced age, congenital predisposition, or the like.
For these reasons, it would be desirable to provide improved devices, methods, and systems for treating the support tissues of the body. It would be particularly desirable to provide techniques for treatment of incontinence and other conditions by enhancing the support of the body""s own tissue systems. It would further be advantageous if these improved techniques could take advantage of the recent advancements in minimally invasive and noninvasive therapies described hereinabove, and could effect treatment with decreased collateral damage. Some or all of these advantages are provided by the invention described hereinbelow.
2. Description of the Background Art
U.S. patent application Ser. Nos. 08/910,370; 09/133,496; 09/170,767; and 09/103,352 are described hereinabove. PCT Application No. 97/43,971 describes a method and apparatus for ablating turbinates. PCT Application No. 98/38,936 describes a method and apparatus for treating venous insufficiency. The impact of surgical treatments of the urethra were described by Shlomo Raz in FEMALE UROLOGY, 2nd Ed. (1996). This reference also describes techniques of surgical repair for treatment of cystocele on pages 340-342, while various alternative known surgical interventions for treatment of incontinence are schematically illustrated on page 356. At least some of these procedures are also described in FEMALE PELVIC DISORDERS, INVESTIGATION AND MANAGEMENT by J. Thomas Benson (1992) on pages 239-240.
An electrosurgical probe for the controlled contraction of tissues of joints and for dermatological indications is described in U.S. Pat. No. 5,458,596. A bipolar electrosurgical probe having electrodes formed over a restricted arc of its distal end for treatment of, for example, the esophagus, is described in U.S. Pat. No. 4,765,331. Systems and methods for electrosurgical cutting and ablation are described in U.S. Pat. No. 5,697,882. Methods and apparatus for controlled contraction of soft tissues is described in U.S. Pat. No. 5,569,242. U.S. Pat. No. 5,423,811 describes a method for RF ablation using cooled electrodes.
The present invention provides improved methods, devices, and systems for treating the support structures of the body, as a treatment for incontinence and other conditions. In general, the invention takes advantage of two mechanisms to enhance the support provided by the fascia, ligaments and tendons: first, the invention increases a modulus of elasticity of these tissues, and particularly of the fascial tissues. The increase in modulus can be effected by directing sufficient energy to the fascial tissue so as to promote the formation of scar tissue. The resulting scarred tissue is generally significantly less elastic than the original fascia, and may also have an increased thickness (either as the result of fascial shrinkage or from the proliferation of scar tissue and/or smooth muscle cells). This local increase in modulus of the scarred support tissue can transfer stress and strain from the area of treatment to adjoining areas, and may also shorten the response time of the tissue plane to stress pulses (such as those which might result in incontinence events).
The second mechanism encompassed by the invention for enhancing the support is to promote attachment of adjacent support tissues to each other. Adjacent fascial tissue surfaces in the pelvic support system are often able to slide freely against each other. This free lateral movement allows the visceral organs to expand and contract over time. However, if there is inadequate support, the motion may become extreme and result in incontinence, prolapse, and other conditions. By directing energy (for example) at the interface between sliding fascial tissue surfaces, the relative motion at the interface can be restricted so as to enhance support of the pelvic viscera. Heating may be used to induce acute (through tissue fusion) and/or chronic (through the growth of cross-linked collagenated tissue or adhesions) attachments between the tissues.
In a first aspect, the invention provides a method for treating incontinence. The method comprises reducing an elasticity of a pelvic support tissue system sufficiently so that the tissue system inhibits incontinence. Generally, the elasticity will be reduced by promoting scarring of fascia supporting the urethra and/or bladder. The scarring reduces the modulus of elasticity of the fascial tissue so that the fascial tissue inhibits incontinence. Such scarring will preferably be promoted by directing energy into the fascial tissue so as to injure the fascial tissue without ablating the fascial tissue. While such energy can be delivered in the form of ultrasound, microwave, laser, or thermal conduction, it will preferably be in the form of an RF current conducted through the tissue so that the tissue""s impedance effects heating.
Advantageously, heating the fascial tissue to a temperature of about 45xc2x0 C. or more is sufficient to promote the formation of scar tissue and thereby decrease elasticity. Hence, elasticity can be reduced by heating the tissue below the temperatures generally used to effect contraction or shrinkage (typically over about 60xc2x0 C.). These lower tissue temperatures can significantly reduce collateral damage, particularly where the elasticity of the tissue is reduced without significant shrinkage. As elasticity reduction and shrinking represent two distinct structural alterations in the tissue system, they may be applied independently or in selective combinations so as to provide the desired change in structural support.
Typically, the elasticity of the tissue is reduced along a length of tissue. The tissue will be susceptible to loading along this length by an incontinence-event stress such as coughing, laughing, exercise, or the like. Reduction in the elasticity may be provided with or without selective reduction in the length (typically by collagenous tissue shrinkage). The present invention allows selective tailoring of an incontinence therapy in response to a comparison between a change in urethral pressure relative to a change in vesical pressure during an incontinence event stress pulse.
A variety of tissues and tissue structures may be targeted for the present incontinence treatments. These include the tissue structures and systems of the pelvic floor and/or diaphragm, bladder and urethra, vagina, uterus, bowel, and the like. Treatment modalities include thermal, electrosurgical, laser, focused ultrasound or microwave, and a variety of bioactive or biochemical agents including local drug delivery, caustic compounds, pleurodesis agents, sclerosing agents, growth factors, surgical sealants, and/or the like. When bioactive agents are used, the invention may employ any of a wide variety of available compounds being marketed.
In another aspect, the invention provides a method for treating incontinence. The method comprises promoting attachment between a first tissue and second tissue with energy or an active agent. The second tissue slidingly engages the first tissue prior to attachment, so that the attachment limits motion between the first and second tissues. The limited relative motion of these tissues inhibits incontinence.
Preferably, the attachment promoting step comprises directing sufficient energy to an interface between the first tissue and second tissue to injure a fascial tissue surface without ablating the fascial tissue. The invention encompasses a variety of energy directing mechanisms, with the preferred energy comprising RF current transmitted to the fascial tissue. Typically, first and second fascial tissue surfaces of the first and second tissue will be heated. The heat may acutely fuse the tissue surfaces together. Optionally, collagen of the first and second tissues will be cross-linked during the healing process. In other embodiments, the attachment promoting step may result in the formation of adhesions between the first and second tissues. Surprisingly, although the prevention of adhesion formation is an important goal of many pelvic surgeries, controlled adhesion generation may result in significant patient benefit where the adhesion serves to enhance the support of the pelvic viscera.
In another aspect, the invention provides a method for treating incontinence. This method comprises measuring a urethral pressure and a vesicle pressure during a stress. A change in the measured urethral pressure is compared relative to a change in the measured vesicle pressure. An elasticity of a pelvic support system is reduced in response to the comparing step sufficiently that the urethral pressure will remain greater than the vesicle pressure during stress.
In yet another aspect, the invention provides a system to treat incontinence. The system comprises a probe for delivering energy or an active agent to a pelvic support tissue so as to reduce an elasticity of the pelvic support tissue. A control system is coupled to the probe. The control system limits the delivery from the probe to avoid collateral damage.
In many embodiments, the control system will limit an amount of the energy or the agent to avoid shrinkage of the tissue. The probe will preferably comprise an energy delivery member, ideally comprising an RF electrode. The exemplary system further includes a urethral pressure sensor, a vesicle pressure sensor, and a processor coupled to the urethral and vesicle pressure sensors. The processor generates an output indicating a change in urethral pressure relative to a change in vesicle pressure. This output is particularly useful for determining the desired reduction in elasticity of the pelvic support tissue.
In another aspect, the invention provides a kit for treating incontinence. The kit comprises a probe for directing energy or a bioactive agent to a pelvic tissue system. Instructions for using the probe will describe methods for enhancing structural support provided by the tissue system so that incontinence is inhibited. The instructions and probe may be packaged together, and the method steps of the instructions may be any of the methods described herein.